package chroya.demo.rotate3d;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Camera;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.view.MotionEvent;
import android.view.View;

/**
 * 图片三维翻转
 * @author chroya
 */
public class CubeView extends View {
	//摄像机
	private Camera mCamera;
	
	//翻转用的图片
	private Bitmap face;	
	private Matrix mMatrix = new Matrix();
	private Paint mPaint = new Paint();

	private int mLastMotionX, mLastMotionY;
	
	//图片的中心点坐标
	private int centerX, centerY;
	//转动的总距离，跟度数比例1:1
	private int deltaX, deltaY;
	//图片宽度高度
	private int bWidth, bHeight;
	
	public CubeView(Context context) {
		super(context);
		setWillNotDraw(false);
		mCamera = new Camera();	
		mPaint.setAntiAlias(true);
		face = BitmapFactory.decodeResource(getResources(), R.drawable.x);
		bWidth = face.getWidth();
		bHeight = face.getHeight();
		centerX = bWidth>>1;//相当于除以2
		centerY = bHeight>>1;
	}	
	
	/**
	 * 转动
	 * @param degreeX
	 * @param degreeY
	 */
	void rotate(int degreeX, int degreeY) {
		deltaX += degreeX;
		deltaY += degreeY;
		
		mCamera.save();
		mCamera.rotateY(deltaX);
		mCamera.rotateX(-deltaY);
		mCamera.translate(0, 0, -centerX);
		mCamera.getMatrix(mMatrix);
		mCamera.restore();	
		//以图片的中心点为旋转中心,如果不加这两句，就是以（0,0）点为旋转中心
		mMatrix.preTranslate(-centerX, -centerY);
		mMatrix.postTranslate(centerX, centerY);		
		mCamera.save();	
		
		postInvalidate();
	}	
	
	@Override
	public boolean onTouchEvent(MotionEvent event) {
		int x = (int) event.getX();
		int y = (int) event.getY();
		
		switch(event.getAction()) {
		case MotionEvent.ACTION_DOWN:
			mLastMotionX = x;
			mLastMotionY = y;
			break;
		case MotionEvent.ACTION_MOVE:
			int dx = x - mLastMotionX;
			int dy = y - mLastMotionY;
			rotate(dx, dy);
			mLastMotionX = x;
			mLastMotionY = y;
			break;
		case MotionEvent.ACTION_UP:
			break;
		}
		return true;
	}
	
	@Override
	public void dispatchDraw(Canvas canvas) {
		super.dispatchDraw(canvas);
		canvas.drawBitmap(face, mMatrix, mPaint);		
	}
}
